1. Field of the Invention
This invention relates to dental articulator apparatus, and particularly to upper and lower dental mold forms within which upper and lower tooth forms, or portions thereof, may be cast, removed from the mold forms, segmented as necessary, and the segments accurately repositioned and retained in the mold form.
2. Description of the Prior Art
A preliminary patentability and novelty search has revealed the existence of the following patents:
All of the above listed patents relate to the subject matter of fabricating dental devices by one method or another, and utilize an articulator device of one design or another. However, as will readily be apparent from a detailed examination of the patents listed above, they involve complex procedures and complex equipment that requires a great deal of training and skill to operate to fabricate artificial dental devices having the precise size and configuration that is required by the dental profession. Specifically, the process taught by the patents listed above involve the use of too much labor and the use of too much xe2x80x9cstonexe2x80x9d, which is the material that is utilized to replicate a patient""s mouth and teeth from the impression that is delivered to the dental laboratory by a dentist.
It will of course be understood that when a dentist utilizes a hardenable plastic material to make an impression of a patient""s teeth, the mass of hardenable plastic material is permitted to harden in the patient""s mouth until the exact configuration of the teeth and gum structure of the patient is impressed in the material, thus creating a xe2x80x9cnegativexe2x80x9d of the patient""s dental pattern, be it the entire number of upper and lower teeth, or only a portion of either or both of the upper and lower teeth. These impressions that are made by the dentist and supplied to the dental laboratory replicate with considerable exactitude and precision the configuration of the patient""s teeth and particularly the occlusive surfaces thereof which of course must match exactly in opposing teeth in the upper and lower jaws.
The impression thus made by the dentist is then sent to the dental laboratory and under conventional circumstances, the impression would be utilized to reproduce in a hardenable material such as xe2x80x9cstonexe2x80x9d commonly used by dental laboratory technicians the exact pattern and configuration that is represented by the xe2x80x9cnegativexe2x80x9d impressions taken from the patient""s mouth. By conventional methods and conventional articulators as illustrated in the patent listed above, the reproduction of the patient""s crown pattern is a labor intensive process, thus increasing the cost of the work to both the dentist and to the patient. Accordingly, it is one of the objects of the present invention to simplify the process of reproducing the exact configuration and pattern of the patient""s teeth through utilization of a novel dental articulator that is less costly to produce and requires less skill to utilize to produce dental casts of a patient""s teeth.
Another object of the invention is the provision of a dental articulator apparatus or kit that utilizes selectively, dental casting molds for specific portions of a patient""s dental array.
A still further object of the invention is the provision of a dental articulator apparatus and kit in which a mold is utilized in which the dental pattern of a patient is cast in dental stone, which cast can then be removed from the mold after hardening, individual teeth in the casting can then be separated one from the other and then reinserted into the mold and retained in exactly the same position in which they were initially cast so that any one or a number of the multiple teeth initially cast may be individually or as a group removed from the casting mold to enable the dental technician to complete the operation of forming an individual or a multiple denture structure for the patient that will fit precisely in the patient""s mouth without the necessity of laborious and time consuming and expensive trimming in order to make the artificial dental device fit the patient""s mouth.
A still further object of the invention is the provision of a dental casting mold that incorporates peripheral locating lugs in the base of the mold that creates recesses of complementary configuration and location in the dental casting cast in the mold, so that when the dental casting is removed from the mold, it may be replaced in exactly the same position in which it was originally cast because the recesses made in the casting correspond to the locating lugs or xe2x80x9cfilletsxe2x80x9d formed in the mold.
A still further object of the invention is the provision of a method and means of permanently embedding one or more guide tubes in the dental casting through which a removable metal guide pin may be inserted and supported on the mold prior to pouring the dental pattern, and which forms an elongated sleeve embedded in the casting and enables the dental pattern and the sleeve to be cut into multiple independent tooth segments and reinserted into the mold as individual teeth and retained in exactly the same position in which such casting was initially produced by reinsertion of the metal pin through the now segmented sleeve and body of the casting.
Yet another object of the invention is the provision of two alternate embodiments of the dental articulator apparatus of the invention, the differences between the two embodiments involving simplification of structure and facility of use.
A still further object of the invention is the provision of a dental articulator apparatus in which opposing dental casting mold plates are automatically and simultaneously resiliently centered in relation to a supporting stanchion so as to provide exact correspondence between upper and lower tooth castings.
Another object of the invention is the provision of a dental articulator apparatus incorporating a mold plate retention stanchion, and means resiliently and releasably retaining the mold plates on the retention stanchion, and enabling pivotal displacement of the mold plates in relation to the retention stanchion to change their orientation in relation thereto while retaining the mold plates releasably secured to the retention stanchion.
A still further object of the invention is the provision of a press structure that cooperates with the dental articulator tray or mold to eject the stone dental casting from the mold after the casting has hardened.
The invention possesses other objects and features of advantage, some of which, with the foregoing, will be apparent from the following description and the drawings. It is to be understood however that the invention is not limited to the embodiment illustrated and described, since it may be embodied in various forms within the scope of the appended claims.
In terms of broad inclusion, the dental articulator apparatus of the invention in one preferred embodiment includes a base plate fixedly secured by one end to a monolithic stanchion or main support bar or plate that normally extends from the base plate perpendicularly and which at its top end pivotally supports a top plate that may be articulated from a horizontal position to a vertical position, and which is detachably secured to the upper end of the stanchion or support plate. On confronting surfaces of the top plate and base plate, are formed mold cavities the walls of which project perpendicularly from the confronting surfaces of the top and base plates, so that the mold cavities confront one another, in much the same manner that the upper and lower set of teeth in a patient""s mouth confront one another when the mouth is closed. The mold cavities formed in the base and top plate are utilized to receive dental xe2x80x9cstonexe2x80x9d that has been mixed to a consistency to be xe2x80x9cworkablexe2x80x9d yet not be liquidous or runny, so that each of the cavities can be independently filled with the still plastic xe2x80x9cstonexe2x80x9d and the xe2x80x9cnegativexe2x80x9d impression received from the dentist superimposed over the stone filled cavity so as to reconstruct the xe2x80x9cpositivexe2x80x9d impression of the patient""s teeth in stone when it sets up and hardens. It is important to note that the dental xe2x80x9cstonexe2x80x9d should be vibrated in the mold cavity so as to remove air bubbles that may be entrained in the mixture when the xe2x80x9cstonexe2x80x9d in powdered form is mixed with water to render it xe2x80x9cplasticxe2x80x9d or xe2x80x9cworkablexe2x80x9d. Once the dental stone casting has hardened, means are provided for ejecting the dental stone casting from the mold cavity in which it is formed. Embedded in the hardened dental stone casting is an elongated tubular sleeve, preferably fabricated from a suitable plastic material. The outer diameter of the tubular sleeve is conveniently approximately xe2x85x9 of an inch or less, and the hollow interior of the plastic tube snubly yet slidably accommodates a metal guide pin that passes through two appropriate apertures formed in the mold wall while the ends of the plastic tube abut the inner surface of the mold cavity. When the dental stone casting has hardened, and it is desired to remove the dental stone casting from the mold cavity, the guide pin is removed by sliding it out of the plastic sleeve, which remains embedded in the stone casting. The mold plate is appropriately mounted in a press that is manipulated to eject the xe2x80x9cpositivexe2x80x9d dental casting from the mold as one monolithic body. The plastic tubular sleeve remains embedded in the monolithic body when it is ejected from the mold cavity. Thereafter, the monolithic dental casting may be segmented so as to separate one stone xe2x80x9ctoothxe2x80x9d from another. The process of separation is conveniently effected with an appropriate stone cutting electrically driven saw or a fine tooth hand saw. The segmenting process severs the embedded tubular sleeve so that a portion thereof remains in each of the stone tooth segments that have been separated from the remainder of the casting. Additionally, orienting lugs are formed in the lower peripheral portion of the mold cavities so that the dental castings, when separated, may be reinstated into the casting cavity in exactly the same position in which they were originally cast by virtue of orienting lugs fitting snugly in complementary recesses formed in the stone casting. Additionally, because the tubing imbedded in each of the now separated dental casting segments remains embedded, the separated dental casting segment of each of the teeth, or group of teeth, when reinstated into the mold cavity in its identical original position in which it was originally cast, may be secured in that position by reinserting the guide pin through the aligned tubular sleeve segments embedded in the separated tooth castings. Preferably, a full set of mold cavities includes a mold cavity for the front teeth comprising the central incisors, lateral incisors, and canine teeth, while another set of cavity molds includes the left and right side molars extending from the first pre-molar to at least the second molar and perhaps even the third molar which constitutes the wisdom tooth. The third set of mold cavities is designed to encompass all of the upper and lower teeth in a patient""s mouth. In another preferred embodiment, both the base plate and top plate are pivotally and slidably mounted on the retaining stanchion for universal accommodation of upper xe2x80x9cteethxe2x80x9d with lower xe2x80x9cteethxe2x80x9d in the same manner in which the mandibular joints in the human jaw function to accommodate upper and lower teeth in humans.